# HydroFoo vs Pillar

The clearest difference is update cadence: Pillar at every 10 days against HydroFoo's every 2 months. HydroFoo's advantage is device support (3 vs 1). On price, ads, in-app purchases and iOS requirement there is nothing between them.

Both are free to download. HydroFoo sells 2 in-app purchases, starting at $1.99 per month and Pillar sells 2 in-app purchases, starting at $7.99 per 7 days. Whichever you choose, the download price is not the number that matters.

HydroFoo ships an update every 2 months, Pillar every 10 days. The most recent releases landed on October 10, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | HydroFoo | Pillar |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/pillar-posture-reminder/id6809597345/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 10 days** |
| Monetization | — | Freemium |
| Size | 20 MB | 27 MB |
| Requires iOS | **17.0** | 18.0 |
| Devices | **iPhone, iPad, Apple Watch** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [GARRETT MICHAEL WOODSIDE](https://appshunter.io/developer/1853175827) | [Maksym Pustovit](https://appshunter.io/developer/1886895390) |

## What reviewers say

### HydroFoo

[App page](https://appshunter.io/ios/app/hydrofoo-water-tracker/id6760419525)

**Features:** macOS Compatibility, Family Sharing, Apple Watch app, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| HydroFoo Pro Monthly | $1.99 | per month |
| HydroFoo Pro Lifetime | $12.99 | one-time |


### Pillar

[App page](https://appshunter.io/ios/app/pillar-posture-reminder/id6809597345)

Improve your posture and focus with this app that uses your AirPods' motion sensors to detect slouching. It provides gentle nudges and tracks your progress over time, integrating with Pomodoro timers for enhanced productivity. No camera or extra wearables are required.

**Highlights:** Live posture reading via AirPods motion sensors, Gentle, responsive nudges for slouching, Integrated Pomodoro focus and break timer, Daily tall-time goal and streak tracking, Weekly trend and session insights, Live Activity and widget support

**Features:** macOS Compatibility, Family Sharing, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pillar Premium Weekly | $7.99 | per 7 days |
| Pillar Premium Yearly | $28.99 | per year |


## Frequently asked questions

### Is HydroFoo free?

HydroFoo is free to download, with in-app purchases available.

### Is Pillar free?

Pillar is free to download, with in-app purchases available.

### Do HydroFoo or Pillar have ads?

Neither HydroFoo nor Pillar shows ads.

### Which is updated more often, HydroFoo or Pillar?

HydroFoo ships an update every 2 months, and Pillar every 10 days. Most recently, HydroFoo was updated on October 10, 2026 and Pillar on October 7, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*